Polyarylene ethers are well known class of engineering thermoplastics. The aromatic portion of the polyarylene ether is thought to contribute to thermal stability and good mechanical properties of the polymer and the ether linkages are considered to facilitate polymer processing while maintaining oxidative and thermal stability.
Polyarylene ethers having an aryl moiety substituted with an electron-withdrawing group are illustrated by the known class of polycyanoaryl ethers represented by the general formula ##STR1## wherein the term Ar represents a variety of arylene species of from 1 to 2 aromatic rings. The cyano group on an aromatic ring appears to promote adhesion of the polymer to many substrates, possibly through polar interaction with other functional groups, and it serves as a potential site for polymer crosslinking. Heath et al, U.S. Pat. No. 3,730,946, discloses polycyano ethers of the above formula wherein Ar is the residue of 2,2-di(4-hydroxyphenyl)propane. Matsuo et al, U.S. Pat. No. 4,640,974, disclose polycyanoaryl ethers of the above formula wherein Ar is a single ring, i.e., phenylene, or has two rings which are fused as in naphthalene or are connected by a valence bond or one of a number of connecting groups.
Such polyaryl ethers have good mechanical properties and a good heat resistance depending in part upon the nature of the Ar group and the nature of the cyano or other electron withdrawing group. The glass transition temperatures of many polycyanoaryl ethers is relatively high with values in the range of from about 150.degree. C. to about 230.degree. C. depending upon the particular Ar group present. It would be of advantage to provide novel polyaryl ethers with even more improved properties and particularly with high glass transition temperatures.